Singh N N, Beale I L
J Exp Anal Behav. 1978 May;29(3):527-33. doi: 10.1901/jeab.1978.29-527.
Eight moderately retarded children were trained on a simultaneous two-choice discrimination problem and a series of discrimination-shift problems. The procedure required the subjects to perform overt observing responses to produce elements of the discriminative stimuli, making it possible to measure directly changes in attention to different aspects of stimuli during learning. The patterns of change in observing responses were generally in line with descriptions of attentional changes derived from two-process theories of discrimination learning; for example, the frequency of irrelevant observing responses was high during the presolution period during extradimensional shifts but was low during intradimensional shifts. Contrary to current theories, extradimensional shifts caused an immediate increase in irrelevant observing responses, and intradimensional shifts usually caused an increase in relevant observing responses. Subjects responded to later shift problems by initially increasing both relevant and irrelevant observing responses, then withholding irrelevant observing responses.
八名中度智障儿童接受了同时进行的二选一辨别问题和一系列辨别转换问题的训练。该程序要求受试者做出公开的观察反应以产生辨别刺激的元素，从而能够直接测量学习过程中对刺激不同方面的注意力变化。观察反应的变化模式总体上与从辨别学习的双过程理论得出的注意力变化描述一致；例如，在维度外转换的解决前阶段，无关观察反应的频率较高，但在维度内转换期间则较低。与当前理论相反，维度外转换导致无关观察反应立即增加，而维度内转换通常导致相关观察反应增加。受试者对后来的转换问题的反应是，最初同时增加相关和无关观察反应，然后抑制无关观察反应。
